Numerous packaging concepts are known in the prior art for displaying a variety of products in many ways. The choice of packaging concept depends greatly upon the ultimate effect which is desired to be presented to the consumer. The blister package of the present invention concerns those situations wherein the blister package desirably is presented to the consumer in a plurality of independent packages, each free-standing vertically on a horizontal support surface. While in some types of packages the vertical support is provided by folded panels of paperboard, this invention pertains to packages in which the support is provided by a reinforced edge incorporated in the blister portion of the total package in cooperation with the edge of the paperboard backing member to which the blister portion is affixed.
Many prior art, vertically self-supporting blister pack display packages are provided with a supporting structure unitarily formed at the bottom of the blister. In one such prior art package, the blister comprises a vertical front wall; a C-shaped side wall; a planar bottom wall between the terminal edges of the C-shaped side wall, said bottom wall having a downward slope intersecting said front wall along a bottom, front edge, said bottom, front edge being a support edge adapted for supporting the entire package on a horizontal surface, in cooperation with the paperboard backing member bottom edge, said blister further including a marginal flange normal to the rear edge of the C-shaped side wall.
An inspection of this known article shows that the minimum thickness exists at the front surface and at the support edge and the greatest thickness exists at the marginal flange. The support edge lacks sufficient strength to withstand normal handling, and minor pressure causes the edge to collapse. Indeed, the entire forward portion of the package is weak, the forward portion receiving the most handling during manufacture and display. The known display package, in fact, attempts to resolve this lack of strength by pouring the product (a melt cast detergent bar) when in molten form directly into the enclosure of the blister, thereby allowing it to conform to the blister's shape. However, contraction of the product mass during cooling occasions an air pocket proximate the support edge, and the inherent weakness in the package remains. Moreover, the negative draft angle occasions damage of the bottom wall during removal of the newly formed blister from molds of conventional construction. Increasing the thickness of the plastic sheet to provide greater strength to the support edge would increase damage to the bottom wall during removal of the newly formed blister from molds of conventional construction.
It is an object of the present invention to provide a vertically self-supporting display package including a molded blister having an undercut.
It is also an object of the present invention to provide a self-supporting blister package including a reinforced support edge unitary with the molded blister.
It is an additional object of the present invention to provide a method for molding a blister including an undercut.
It is yet another object of the present invention to provide a method of molding a blister including an undercut and having a reinforced support edge.
It is a further object of the present invention to provide a self-supporting display package that is relatively lightweight and offers a positive, relatively rigid vertical support.